Liquid crystal composition and liquid crystal display device

ABSTRACT

A liquid crystal composition has a negative dielectric anisotropy and contains a specific compound having large negative dielectric anisotropy as a first component, and a specific compound having small viscosity as a second component. The composition may contain a specific compound having high maximum temperature or small viscosity as a third component, a specific compound having negative dielectric anisotropy as a fourth component, or a specific compound having a polymerizable group as an additive component.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority benefit of Japan Application No. 2015-033916, filed on Feb. 24, 2015. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

TECHNICAL FIELD

The invention relates to a liquid crystal composition, a liquid crystal display device including the composition, and so forth. In particular, the invention relates to a liquid crystal composition having a negative dielectric anisotropy, and a liquid crystal display device that includes the liquid crystal composition and has a mode such as an IPS mode, a VA mode, an FFS mode and an FPA mode. The invention also relates to a liquid crystal display device having a polymer sustained alignment mode.

BACKGROUND ART

In a liquid crystal display device, a classification based on an operating mode for liquid crystals includes a phase change (PC) mode, a twisted nematic (TN) mode, a super twisted nematic (STN) mode, an electrically controlled birefringence (ECB) mode, an optically compensated bend (OCB) mode, an in-plane switching (IPS) mode, a vertical alignment (VA) mode, a fringe field switching (FFS) or a field induced photo-reactive alignment (FPA) mode. A classification based on a driving mode in the device includes a passive matrix (PM) and an active matrix (AM). The PM is further classified into static, multiplex and so forth, and the AM is classified into a thin film transistor (TFT), a metal insulator metal (MIM) and so forth. The TFT is further classified into amorphous silicon and polycrystal silicon. The latter is classified into a high temperature type and a low temperature type according to a production process. A classification based on a light source includes a reflective type utilizing natural light, a transmissive type utilizing backlight and a transflective type utilizing both the natural light and the backlight.

The liquid crystal display device includes a liquid crystal composition having a nematic phase. The composition has suitable characteristics. An AM device having good characteristics can be obtained by improving characteristics of the composition. Table 1 below summarizes a relationship of the characteristics between two aspects. The characteristics of the composition will be further described based on a commercially available AM device. A temperature range of the nematic phase relates to a temperature range in which the device can be used. A preferred maximum temperature of the nematic phase is approximately 70° C. or higher and a preferred minimum temperature of the nematic phase is approximately −10° C. or lower. Viscosity of the composition relates to a response time in the device. A short response time is preferred for displaying moving images on the device. A shorter response time even by one millisecond is desirable. Accordingly, a small viscosity in the composition is preferred. A small viscosity at a low temperature is further preferred.

TABLE 1 Characteristics of Composition and AM Device No. Characteristics of Composition Characteristics of AM Device 1 Wide temperature range of a Wide usable temperature nematic phase range 2 Small viscosity Short response time 3 Suitable optical anisotropy Large contrast ratio 4 Large positive or negative Low threshold voltage and dielectric anisotropy small electric power consumption Large contrast ratio 5 Large specific resistance Large voltage holding ratio and large contrast ratio 6 High stability to ultraviolet Long service life light and heat

An optical anisotropy of the composition relates to a contrast ratio in the device. According to a mode of the device, a large optical anisotropy or a small optical anisotropy, more specifically, a suitable optical anisotropy is required. A product (Δ×d) of the optical anisotropy (Δn) of the composition and a cell gap (d) in the device is designed so as to maximize the contrast ratio. A suitable value of the product depends on the type of the operating mode. The suitable value is in the range of approximately 0.30 micrometer to approximately 0.40 micrometer in a device having the VA mode, and is in the range of approximately 0.20 micrometer to approximately 0.30 micrometer in a device having the IPS mode or the FFS mode. In the above cases, a composition having the large optical anisotropy is preferred for a device having a small cell gap. A large dielectric anisotropy in the composition contributes to a low threshold voltage, a small electric power consumption and a large contrast ratio in the device. Accordingly, the large dielectric anisotropy is preferred. A large specific resistance in the composition contributes to a large voltage holding ratio and the large contrast ratio in the device. Accordingly, a composition having a large specific resistance at room temperature and also at a temperature close to the maximum temperature of the nematic phase in an initial stage is preferred. A composition having a large specific resistance at room temperature and also at a temperature close to the maximum temperature of the nematic phase even after the device has been used for a long period of time is preferred. Stability of the composition to ultraviolet light and heat relates to a service life of the liquid crystal display device. In the case where the stability is high, the device has a long service life. Such characteristics are preferred for an AM device for use in a liquid crystal projector, a liquid crystal television and so forth.

In a liquid crystal display device having a polymer sustained alignment (PSA) mode, a liquid crystal composition containing a polymer is used. First, a composition to which a small amount of polymerizable compound is added is injected into the device. Then, the composition is irradiated with ultraviolet light while voltage is applied between substrates of the device. The polymerizable compound polymerizes to form a network structure of the polymer in the liquid crystal composition. In the composition, alignment of liquid crystal molecules can be controlled by the polymer, and therefore the response time of the device is shortened and also image persistence is improved. Such an effect of the polymer can be expected for a device having the mode such as the TN mode, the ECB mode, the OCB mode, the IPS mode, the VA mode, the FFS mode and the FPA mode.

A composition having a positive dielectric anisotropy is used for an AM device having the TN mode. In an AM device having the VA mode, a composition having a negative dielectric anisotropy is used. A composition having the positive or negative dielectric anisotropy is used for an AM device having the IPS mode or the FFS mode. A composition having a positive or negative dielectric anisotropy is used for an AM device having the polymer sustained alignment mode. Examples of first components of the application are disclosed in the following Patent documents 1 to 3.

CITATION LIST Patent Literature

Patent literature No. 1: JP 2009-507759 A.

Patent literature No. 2: JP 2008-545669 A.

Patent literature No. 3: JP 2008-545671 A.

SUMMARY OF INVENTION Technical Problem

The invention provides a liquid crystal composition satisfying at least one of characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of the nematic phase, a small viscosity, a suitable optical anisotropy, a large negative dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light and a high stability to heat. The invention also provides a liquid crystal composition having a suitable balance regarding at least two of the characteristics. The invention further provides a liquid crystal display device containing such a composition. The invention yet further provides an AM device having characteristics such as a short response time, a large voltage holding ratio, a low threshold voltage, a large contrast ratio and a long service life.

Solution to Problem

The invention concerns a liquid crystal composition that has a negative dielectric anisotropy and contains at least one compound selected from the group of compounds represented by formula (1) as a first component and at least one compound selected from the group of compounds represented by formula (2) as a second component, and concerns a liquid crystal display device containing the composition:

wherein, in formula (1) and formula (2), R¹ and R² are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkenyloxy having 2 to 12 carbons, or alkyl having 1 to 12 carbons in which at least one of hydrogen is replaced by fluorine or chlorine; R³ and R⁴ are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkyl having 1 to 12 carbons in which at least one of hydrogen is replaced by fluorine or chlorine or alkenyl having 2 to 12 carbons in which at least one of hydrogen is replaced by fluorine or chlorine; ring A and ring C are independently 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 3,4-dihydro-2H-pyrane-2,5-diyl, 1,4-phenylene, 1,4-phenylene in which at least one of hydrogen is replaced by fluorine or chlorine, naphthalene-2,6-diyl, naphthalene-2,6-diyl in which at least one of hydrogen is replaced by fluorine or chlorine, chroman-2,6-diyl, or chroman-2,6-diyl in which at least one of hydrogen is replaced by fluorine or chlorine, in which at least one of ring A and ring C is 3,4-dihydro-2H-pyrane-2,5-diyl; ring B is 2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5-trifluoronaphthalene-2,6-diyl or 7,8-difluorochroman-2,6-diyl; Z¹ and Z² are independently a single bond, ethylene, carbonyloxy or methyleneoxy; a is 1, 2, or 3; b is 0 or 1; and a sum of a and b is 3 or less.

Advantageous Effects of Invention

One of the advantages of the invention is a liquid crystal composition satisfying at least one of characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of the nematic phase, a small viscosity, a suitable optical anisotropy, a large negative dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light and a high stability to heat. Another advantage is a liquid crystal composition having a suitable balance regarding at least two of the characteristics. Another advantage is a liquid crystal display device including such a composition. Another advantage is an AM device having characteristics such as a short response time, a large voltage holding ratio, a low threshold voltage, a large contrast ratio and a long service life.

DESCRIPTION OF EMBODIMENTS

Usage of terms herein is as described below. Terms “liquid crystal composition” and “liquid crystal display device” may be occasionally abbreviated as “composition” and “device,” respectively. “Liquid crystal display device” is a generic term for a liquid crystal display panel and a liquid crystal display module. “Liquid crystal compound” is a generic term for a compound having a liquid crystal phase such as a nematic phase and a smectic phase, and a compound having no liquid crystal phase but to be mixed with a composition for the purpose of adjusting characteristics such as a temperature range of the nematic phase, viscosity and dielectric anisotropy. The compound has a six-membered ring such as 1,4-cyclohexylene and 1,4-phenylene, and rod like molecular structure. “Polymerizable compound” is added for the purpose of forming a polymer in the composition.

The liquid crystal composition is prepared by mixing a plurality of liquid crystal compounds. A ratio (content) of the liquid crystal compounds is expressed in terms of weight percent (% by weight) based on the weight of the liquid crystal composition. An additive such as an optically active compound, an antioxidant, an ultraviolet light absorber, a dye, an antifoaming agent, the polymerizable compound, a polymerization initiator and a polymerization inhibitor is added to the liquid crystal composition when necessary. A ratio (content) of the additive is expressed in terms of weight percent (% by weight) based on the weight of the liquid crystal composition in a manner similar to the ratio of the liquid crystal compound. Weight parts per million (ppm) may be occasionally used. A ratio of the polymerization initiator and the polymerization inhibitor is exceptionally expressed based on the weight of the polymerizable compound.

“Maximum temperature of the nematic phase” may be occasionally abbreviated as “maximum temperature.” “Minimum temperature of the nematic phase” may be occasionally abbreviated as “minimum temperature.” An expression “having a large specific resistance” means that the composition has a large specific resistance at room temperature and also at a temperature close to the maximum temperature of the nematic phase in an initial stage, and that the composition has a large specific resistance at room temperature and also at a temperature close to the maximum temperature of the nematic phase even after the device has been used for a long period of time. An expression “having a large voltage holding ratio” means that the device has a large voltage holding ratio at room temperature and also at a temperature close to the maximum temperature of the nematic phase in an initial stage, and that the device has a large voltage holding ratio at room temperature and also at a temperature close to the maximum temperature of the nematic phase even after the device has been used for a long period of time. An expression “to increase the dielectric anisotropy” means that a value of dielectric anisotropy positively increases in a liquid crystal composition having a positive dielectric anisotropy, and the value of dielectric anisotropy negatively increases in a liquid crystal composition having a negative dielectric anisotropy.

The compound represented by formula (1) may be abbreviated as “compound (1).” At least one compound selected from the group of compounds represented by formula (2) may be abbreviated as “compound (2).” “Compound (1)” means one compound, a mixture of two compounds or a mixture of three or more compounds represented by formula (1). A same rule applies to any other compound represented by any other formula. An expression “at least one of ‘A’” means that the number of ‘A’ is arbitrary. An expression “at least one of ‘A’ may be replaced by ‘B’” means that a position of ‘A’ is arbitrary when the number of ‘A’ is 1, and the positions can be selected without limitation also when the number of ‘A’ is 2 or more. A same rule also applies to an expression “at least one of ‘A’ is replaced by ‘B’.”

A symbol of terminal group R¹ is used for a plurality of compounds in chemical formulas of component compounds. In the compounds, two groups represented by two of arbitrary R¹ may be identical or different. In one case, for example, R¹ of compound (1-1) is ethyl and R¹ of compound (1-2) is ethyl. In another case, R¹ of compound (1-1) is ethyl and R¹ of compound (1-2) is propyl. A same rule also applies to any other symbol of a terminal group or the like. In formula (3), when d is 2, two of ring C exist. In the compound, two rings represented by two of ring C may be identical or different. A same rule applies to two of arbitrary ring C when d is larger than 2. A same rule is also applied to a symbol Z¹, ring A or the like. A same rule also applies to a case of two of -Sp²-P⁵ or the like in compound (5-27).

A symbol A, B, C or the like surrounded by a hexagonal shape corresponds to a six-membered ring such as ring A, ring B and ring C, or the like, respectively. In compound (5), a hexagonal shape represents a six-membered ring or a condensed ring. An oblique line crossing the hexagonal shape means that arbitrary hydrogen on the ring may be replaced by a group such as -Sp¹-P¹. A subscript such as h represents the number of groups subjected to replacement. When the subscript is 0, no such replacement is made. When h is two or more, a plurality of -Sp¹-P¹ exist on ring K. The plurality of groups represented by -Sp¹-P¹ may be identical or may be different.

Then, 2-fluoro-1,4-phenylene means two divalent groups described below. In the chemical formula, fluorine may be leftward (L) or rightward (R). A same rule also applies to an asymmetrical divalent group derived from a ring, such as tetrahydropyran-2,5-diyl. A same rule applies also to a divalent bonding group such as carbonyloxy (—COO— or —OCO—).

The invention includes the items described below.

Item 1. A liquid crystal composition that has a negative dielectric anisotropy and contains at least one compound selected from the group of compounds represented by formula (1) as a first component and at least one compound selected from the group of compounds represented by formula (2) as a second component:

wherein, in formula (1) and formula (2), R¹ and R² are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkenyloxy having 2 to 12 carbons, or alkyl having 1 to 12 carbons in which at least one of hydrogen is replaced by fluorine or chlorine; R³ and R⁴ are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkyl having 1 to 12 carbons in which at least one of hydrogen is replaced by fluorine or chlorine or alkenyl having 2 to 12 carbons in which at least one of hydrogen is replaced by fluorine and chlorine; ring A and ring C are independently 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 3,4-dihydro-2H-pyrane-2,5-diyl, 1,4-phenylene, 1,4-phenylene in which at least one of hydrogen is replaced by fluorine or chlorine, naphthalene-2,6-diyl, naphthalene-2,6-diyl in which at least one of hydrogen is replaced by fluorine or chlorine, chroman-2,6-diyl, or chroman-2,6-diyl in which at least one of hydrogen is replaced by fluorine or chlorine, in which at least one of ring A and ring C is 3,4-dihydro-2H-pyrane-2,5-diyl; ring B is 2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5-trifluoronaphthalene-2,6-diyl, or 7,8-difluorochroman-2,6-diyl; Z¹ and Z² are independently a single bond, ethylene, carbonyloxy or methyleneoxy; a is 1, 2 or 3; b is 0 or 1; and a sum of a and b is 3 or less.

Item 2. The liquid crystal composition according to item 1, containing at least one compound selected from the group of compounds represented by formula (1-1) to formula (1-7) as the first component:

wherein, in formula (1-1) to formula (1-7), R¹ and R² are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkenyloxy having 2 to 12 carbons, or alkyl having 1 to 12 carbons in which at least one of hydrogen is replaced by fluorine or chlorine.

Item 3. The liquid crystal composition according to item 1 or 2, wherein a ratio of the first component is in the range of 5% by weight to 40% by weight and a ratio of the second component is in the range of 10% by weight to 60% and by weight, based on the weight of the liquid crystal composition.

Item 4. The liquid crystal composition according to any one of items 1 to 3, containing at least one compound selected from the group of compounds represented by formula (3) as a third component:

wherein, in formula (3), R⁵ and R⁶ are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkyl having 1 to 12 carbons in which at least one of hydrogen is replaced by fluorine or chlorine or alkenyl having 2 to 12 carbons in which at least one of hydrogen is replaced by fluorine or chlorine; ring C and ring D are independently 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene or 2,5-difluoro-1,4-phenylene; Z³ is a single bond, ethylene or carbonyloxy; d is 1, 2 or 3; and in which, when d is 1, ring D is 1,4-phenylene.

Item 5. The liquid crystal composition according to any one of items 1 to 4, containing at least one compound selected from the group of compounds represented by formula (3-1) to (3-12) as the third component:

wherein, in formulas (3-1) to (3-12), R⁵ and R⁶ are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkyl having 1 to 12 carbons in which at least one of hydrogen is replaced by fluorine or chlorine or alkenyl having 2 to 12 carbons in which at least one of hydrogen is replaced by fluorine or chlorine.

Item 6. The liquid crystal composition according to item 4 or 5, wherein a ratio of the third component is in the range of 5% by weight to 40% by weight based on the weight of the liquid crystal composition.

Item 7. The liquid crystal composition according to any one of items 1 to 6, containing at least one compound selected from the group of compounds represented by formula (4) as a fourth component:

wherein, in formula (4), R⁷ and R⁸ are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkenyloxy having 2 to 12 carbons, or alkyl having 1 to 12 carbons in which at least one of hydrogen is replaced by fluorine or chlorine; ring E and ring G are independently 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,4-phenylene, 1,4-phenylene in which at least one of hydrogen is replaced by fluorine or chlorine, naphthalene-2,6-diyl, naphthalene-2,6-diyl in which at least one of hydrogen is replaced by fluorine or chlorine, chroman-2,6-diyl, or chroman-2,6-diyl in which at least one of hydrogen is replaced by fluorine or chlorine; ring F is 2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5-trifluoronaphthalene-2,6-diyl or 7,8-difluorochroman-2,6-diyl; Z⁴ and Z⁵ are independently a single bond, ethylene, carbonyloxy or methyleneoxy; p is 1, 2 or 3; q is 0 or 1; and a sum of p and q is 3 or less.

Item 8. The liquid crystal composition according to any one of items 1 to 7, containing at least one compound selected from the group of compounds represented by formula (4-1) to formula (4-19) as the fourth component:

wherein, in formula (4-1) to formula (4-19), R⁷ and R⁸ are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkenyloxy having 2 to 12 carbons, or alkyl having 1 to 12 carbons in which at least one of hydrogen is replaced by fluorine or chlorine.

Item 9. The liquid crystal composition according to item 7 or 8, wherein a ratio of the fourth component is in the range of 10% by weight to 70% by weight based on the weight of the liquid crystal composition.

Item 10. The liquid crystal composition according to any one of items 1 to 9, containing at least one polymerizable compound selected from the group of compounds represented by formula (5) as an additive component:

wherein, in formula (5), ring K and ring M are independently cyclohexyl, cyclohexenyl, phenyl, 1-naphthyl, 2-naphthyl, tetrahydropyran-2-yl, 1,3-dioxane-2-yl, pyrimidine-2-yl or pyridine-2-yl, and in the rings, at least one of hydrogen may be replaced by fluorine, chlorine, alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkyl having 1 to 12 carbons in which at least one of hydrogen is replaced by fluorine or chlorine; ring L is 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, naphthalene-1,2-diyl, naphthalene-1,3-diyl, naphthalene-1,4-diyl, naphthalene-1,5-diyl, naphthalene-1,6-diyl, naphthalene-1,7-diyl, naphthalene-1,8-diyl, naphthalene-2,3-diyl, naphthalene-2,6-diyl, naphthalene-2,7-diyl, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl or pyridine-2,5-diyl, and in the rings, at least one of hydrogen may be replaced by fluorine, chlorine, alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkyl having 1 to 12 carbons in which at least one of hydrogen is replaced by fluorine or chlorine; Z⁶ and Z⁷ are independently a single bond or alkylene having 1 to 10 carbons, and in the alkylene, at least one of —CH₂— may be replaced by —O—, —CO—, —COO— or —OCO—, at least one of —CH₂—CH₂— may be replaced by —CH═CH—, —C(CH₃)—, ═CH—, —CH═C(CH₃)— or —C(CH₃) ═C(CH₃)—, and in the groups, at least one of hydrogen may be replaced by fluorine or chlorine; P¹, P² and P³ are independently a polymerizable group; Sp¹, Sp² and Sp³ are independently a single bond or alkylene having 1 to 10 carbons, and in the alkylene, at least one of —CH₂— may be replaced by —O—, —COO—, —OCO— or —OCOO—, at least one of —CH₂—CH₂— may be replaced by —CH═CH— or —C≡C—, and in the groups, at least one of hydrogen may be replaced by fluorine or chlorine; g is 0, 1 or 2; and h, j and k are independently 0, 1, 2, 3 or 4, and a sum of h, j and k is 1 or more.

Item 11. The liquid crystal composition according to item 10, wherein, in formula (5), P¹, P² and P³ are independently a polymerizable group selected from the group of groups represented by formula (P-1) to formula (P-6):

wherein, in formula (P-1) to formula (P-6), M¹, M² and M³ are independently hydrogen, fluorine, alkyl having 1 to 5 carbons, or alkyl having 1 to 5 carbons in which at least one of hydrogen is replaced by fluorine or chlorine; and

-   in formula (5), when all of h pieces of P¹ and k pieces of P³ are a     group represented by formula (P-4), at least one of h pieces of Sp¹     and k pieces of Sp³ is alkylene having 1 to 10 carbons in which at     least one of —CH₂— is replaced by —O—, —COO—, —OCO— or —OCOO—.

Item 12. The liquid crystal composition according to any one of items 1 to 11, containing at least one polymerizable compound selected from the group of compounds represented by formula (5-1) to formula (5-27) as the additive component:

wherein, in formula (5-1) to formula (5-27), P⁴, P⁵ and P⁶ are independently a polymerizable group selected from the group of groups represented by formula (P-1) to formula (P-3);

wherein, in formula (P-1) to formula (P-3), M¹, M² and M³ are independently hydrogen, fluorine, alkyl having 1 to 5 carbons, or alkyl having 1 to 5 carbons in which at least one of hydrogen is replaced by fluorine or chlorine; and

-   in formula (5-1) to formula (5-27), Sp¹, Sp² and Sp³ are     independently a single bond or alkylene having 1 to 10 carbons, and     in the alkylene, at least one of —CH₂— may be replaced by —O—,     —COO—, —OCO— or —OCOO—, at least one of —CH₂—CH₂— may be replaced by     —CH═CH— or —C≡C—, and in the groups, at least one of hydrogen may be     replaced by fluorine or chlorine.

Item 13. The liquid crystal composition according to any one of items 10 to 12, wherein a ratio of addition of the additive component is in the range of 0.03% by weight to 10% by weight based on the weight of the liquid crystal composition.

Item 14. A liquid crystal display device, including the liquid crystal composition according to any one of items 1 to 13.

Item 15. The liquid crystal display device according to item 14, wherein an operating mode in the liquid crystal display device includes an IPS mode, a VA mode, an FFS mode or an FPA mode, and a driving mode in the liquid crystal display device includes an active matrix mode.

Item 16. A liquid crystal display device having a polymer sustained alignment mode, wherein the liquid crystal display device includes the liquid crystal composition according to any one of items 1 to 13, or a polymerizable compound in the liquid crystal composition is polymerized.

Item 17. Use of the liquid crystal composition according to any one of items 1 to 13 in a liquid crystal display device.

Item 18. Use of the liquid crystal composition according to any one of items 1 to 13 in a liquid crystal display device having a polymer sustained alignment mode.

The invention further includes the following items: (a) the composition, further containing at least one of additives such as an optically active compound, an antioxidant, an ultraviolet light absorber, a dye, an antifoaming agent, a polymerizable compound, a polymerization initiator or a polymerization inhibitor; (b) an AM device including the composition; (c) a polymer sustained alignment (PSA) mode AM device including the composition further containing a polymerizable compound; (d) the polymer sustained alignment (PSA) mode AM liquid crystal display device, wherein the liquid crystal display device includes the composition and a polymerizable compound in the composition is polymerized; (e) a device including the composition and having a PC mode, a TN mode, an STN mode, an ECB mode, an OCB mode, an IPS mode, a VA mode, an FFS mode or an FPA mode; (f) a transmissive device including the composition; (g) use of the composition as a composition having the nematic phase; and (h) use as an optically active composition by adding the optically active compound to the composition.

The composition of the invention will be described in the following order. First, a constitution of the component compounds in the composition will be described. Second, main characteristics of the component compounds and main effects of the compounds on the composition will be described. Third, a combination of components in the composition, a preferred ratio of the component compounds and basis thereof will be described. Fourth, a preferred embodiment of the component compound will be described. Fifth, a preferred component compound will be shown. Sixth, an additive that may be added to the composition will be described. Seventh, a method for synthesizing the component compound will be described. Last, an application of the composition will be described.

First, the constitution of the component compounds in the composition will be described. The composition of the invention is classified into composition A and composition B. Composition A may further contain any other liquid crystal compound, the additive or the like in addition to the liquid crystal compound selected from compound (1), compound (2), compound (3) and compound (4). “Any other liquid crystal compound” means a liquid crystal compound different from compound (1), compound (2), compound (3) and compound (4). Such a compound is mixed with the composition for the purpose of further adjusting the characteristics. The additive is the optically active compound, the antioxidant, the ultraviolet light absorber, the dye, the antifoaming agent, the polymerizable compound, the polymerization initiator, the polymerization inhibitor or the like.

Composition B consists essentially of compounds selected from the group of compound (1), compound (2), compound (3) and compound (4). An expression “essentially” means that the composition may contain the additive, but contains no any other liquid crystal compound. Composition B has a smaller number of components than composition A has. Composition B is preferred to composition A in view of cost reduction. Composition A is preferred to composition B in view of possibility of further adjusting physical properties by mixing any other liquid crystal compound.

Second, the main characteristics of the component compounds and the main effects of the compounds on the characteristics of the composition will be described. The main characteristics of the component compounds are summarized in Table 2 on the basis of advantageous effects of the invention. In Table 2, a symbol L stands for “large” or “high,” a symbol M stands for “medium,” and a symbol S stands for “small” or “low.” The symbols L, M and S represent a classification based on a qualitative comparison among the component compounds, and 0 (zero) means “a value is zero or nearly zero.”

TABLE 2 Characteristics of Compounds Compound Compound Compound Compound Compounds (1) (2) (3) (4) Maximum temperature S to L M S to L S to L Viscosity M to L S S to M M to L Optical anisotropy M to L S S to L M to L Dielectric anisotropy M to L¹⁾ 0 0 M to L¹⁾ Specific resistance L L L L ¹⁾A compound having a negative dielectric anisotropy.

Upon mixing the component compounds with the composition, the main effects of the component compounds on the characteristics of the composition are as described below. Compound (1) increases the dielectric anisotropy. Compound (2) decreases the viscosity. Compound (3) increases the maximum temperature or decreases the viscosity. Compound (4) increases the dielectric anisotropy and decreases the minimum temperature. Compound (5) is polymerized to give a polymer, and the polymer shortens a response time of the device, and improves image persistence.

Third, the combination of the components in the composition, a preferred ratio of the component compounds and the basis thereof will be described. A preferred combination of the components in the composition includes a combination of the first component and the second component, a combination of the first component, the second component and the third component, a combination of the first component, the second component and the fourth component, a combination of the first component, the second component and the additive component, a combination of the first component, the second component, the third component and the fourth component, a combination of the first component, the second component, the third component and the additive component, a combination of the first component, the second component, the fourth component and the additive component, or a combination of the first component, the second component, the third component, the fourth component and the additive component. A further preferred combination includes the combination of the first component, the second component and the third component, the combination of the first component, the second component, the third component and the fourth component, the combination of the first component, the second component, the third component and the additive component, or the combination of the first component, the second component, the third component, the fourth component and the additive component.

A preferred ratio of the first component is approximately 5% by weight or more for increasing the dielectric anisotropy, and approximately 40% by weight or less for decreasing the minimum temperature. A further preferred ratio is in the range of approximately 5% by weight to approximately 35% by weight. A particularly preferred ratio is in the range of approximately 5% by weight to approximately 30% by weight.

A preferred ratio of the second component is approximately 10% by weight or more for decreasing the viscosity, and approximately 60% or less for increasing the dielectric anisotropy. A further preferred ratio is in the range of approximately 15% by weight to approximately 55% by weight. A particularly preferred ratio is in the range of approximately 20% by weight to approximately 50% by weight.

A preferred ratio of the third component is approximately 5% by weight or more for increasing the maximum temperature or decreasing the viscosity, and approximately 40% or less for increasing the dielectric anisotropy. A further preferred ratio is in the range of approximately 5% by weight to approximately 35% by weight. A particularly preferred ratio is in the range of approximately 10% by weight to approximately 30% by weight.

A preferred ratio of the fourth component is approximately 10% by weight or more for increasing the dielectric anisotropy, and approximately 70% by weight or less for decreasing the minimum temperature. A further preferred ratio is in the range of approximately 15% by weight to approximately 70% by weight. A particularly preferred ratio is in the range of approximately 20% by weight to approximately 65% by weight.

Compound (5) is added to the composition for the purpose of adapting the composition to the polymer sustained alignment mode device. A preferred ratio of the additive component is approximately 0.03% by weight or more for aligning the liquid crystal molecules, and approximately 10% by weight or less for preventing poor display in the device. A further preferred ratio is in the range of approximately 0.1% by weight to approximately 2% by weight. A particularly preferred ratio is in the range of approximately 0.2% by weight to approximately 1.0% by weight.

Fourth, the preferred embodiment of the component compounds will be described. In formula (1), formula (2), formula (3) and formula (4), R¹, R², R⁷ and R⁸ are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkenyloxy having 2 to 12 carbons, or alkyl having 1 to 12 carbons in which at least one of hydrogen is replaced by fluorine or chlorine. Preferred R¹, R², R⁷ or R⁸ is alkyl having 1 to 12 carbons for increasing the stability, or alkoxy having 1 to 12 carbons for increasing dielectric anisotropy. R³, R⁴, R⁵ and R⁶ are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkyl having 1 to 12 carbons in which at least one of hydrogen is replaced by fluorine or chlorine or alkenyl having 2 to 12 carbons in which at least one of hydrogen is replaced by fluorine or chlorine. Preferred R³, R⁴, R⁵ or R⁶ is alkenyl having 2 to 12 carbons for decreasing the viscosity, and alkyl having 1 to 12 carbons for increasing the stability. Alkyl has a straight chain or a branched chain and contains no cyclic alkyl. Straight-chain alkyl is preferred to branched-chain alkyl. A same description applies to a terminal group such as alkoxy and alkenyl.

Preferred alkyl is methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl or octyl. Further preferred alkyl is ethyl, propyl, butyl, pentyl or heptyl for decreasing the viscosity.

Preferred alkoxy is methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy or heptyloxy. Further preferred alkoxy is methoxy or ethoxy for decreasing the viscosity.

Preferred alkenyl is vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl or 5-hexenyl. Further preferred alkenyl is vinyl, 1-propenyl, 3-butenyl or 3-pentenyl for decreasing the viscosity. A preferred configuration of —CH═CH— in the alkenyl depends on a position of a double bond. Trans is preferred in the alkenyl such as 1-propenyl, 1-butenyl, 1-pentenyl, 1-hexenyl, 3-pentenyl and 3-hexenyl for decreasing the viscosity, for instance. Cis is preferred in the alkenyl such as 2-butenyl, 2-pentenyl and 2-hexenyl.

Preferred examples of alkyl in which at least one of hydrogen is replaced by fluorine or chlorine include fluoromethyl, 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl, 5-fluoropentyl, 6-fluorohexyl, 7-fluoroheptyl or 8-fluorooctyl. Further preferred examples include 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl or 5-fluoropentyl for increasing dielectric anisotropy.

Preferred examples of alkenyl in which at least one of hydrogen is replaced by fluorine or chlorine include 2,2-difluorovinyl, 3,3-difluoro-2-propenyl, 4,4-difluoro-3-butenyl, 5,5-difluoro-4-pentenyl or 6,6-difluoro-5-hexenyl. Further preferred examples include 2,2-difluorovinyl or 4,4-difluoro-3-butenyl for decreasing the viscosity.

Ring A and ring C are independently 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 3,4-dihydro-2H-pyrane-2,5-diyl, 1,4-phenylene, 1,4-phenylene in which at least one of hydrogen is replaced by fluorine or chlorine, naphthalene-2,6-diyl, naphthalene-2,6-diyl in which at least one of hydrogen is replaced by fluorine or chlorine, chroman-2,6-diyl, or chroman-2,6-diyl in which at least one of hydrogen is replaced by fluorine or chlorine, in which at least one of ring A and rings C is 3,4-dihydro-2H-pyrane-2,5-diyl. Preferred ring A or ring C is 1,4-cyclohexylene for decreasing the viscosity or for increasing the maximum temperature, and 1,4-phenylene for decreasing the minimum temperature. With regard to a configuration of 1,4-cyclohexylene, trans is preferred to cis for increasing the maximum temperature. Tetrahydropyran-2,5-diyl includes:

and preferably

Then, 3,4-dihydro-2H-pyrane-2,5-diyl includes:

and preferably

Ring B and ring F are independently 2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5-trifluoronaphthalene-2,6-diyl or 7,8-difluorochroman-2,6-diyl. Preferred ring B or ring F is 2,3-difluoro-1,4-phenylene for decreasing the viscosity, 2-chloro-3-fluoro-1,4-phenylene for decreasing the optical anisotropy, and 7,8-difluorochroman-2,6-diyl for increasing dielectric anisotropy.

Ring C and ring D are independently 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene or 2,5-difluoro-1,4-phenylene. Preferred ring C or ring D is 1,4-cyclohexylene for decreasing the viscosity or for increasing the maximum temperature, and 1,4-phenylene for decreasing the minimum temperature.

Ring E and ring G are independently 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,4-phenylene, 1,4-phenylene in which at least one of hydrogen is replaced by fluorine or chlorine, naphthalene-2,6-diyl, naphthalene-2,6-diyl in which at least one of hydrogen is replaced by fluorine or chlorine, chroman-2,6-diyl, or chroman-2,6-diyl in which at least one of hydrogen is replaced by fluorine or chlorine. Preferred ring E or ring G is 2,3-difluoro-1,4-phenylene for decreasing the viscosity, 2-chloro-3-fluoro-1,4-phenylene for decreasing the optical anisotropy, and 7,8-difluorochroman-2,6-diyl for increasing the dielectric anisotropy.

Z¹, Z², Z⁴, and Z⁵ are independently a single bond, ethylene, carbonyloxy or methyleneoxy. Preferred Z¹, Z², Z⁴ or Z⁵ is a single bond for decreasing the viscosity, ethylene for decreasing the minimum temperature and methyleneoxy for increasing the dielectric anisotropy. Z³ is a single bond, ethylene or carbonyloxy. Preferred Z³ is a single bond for increasing the stability.

Then, a is 1, 2 or 3; b is 0 or 1, and a sum of a and b is 3 or less. Preferred a is 1 for decreasing the viscosity and 2 or 3 for increasing the maximum temperature. Preferred b is 0 for decreasing the viscosity, and 1 for decreasing the minimum temperature. Then, d is 1, 2 or 3. Preferred d is 1 for decreasing the viscosity, and 2 or 3 for increasing the maximum temperature. Furthermore, p is 1, 2 or 3, q is 0 or 1, and a sum of p and q is 3 or less. Preferred p is 1 for decreasing the viscosity, and 2 or 3 for increasing the maximum temperature. Preferred q is 0 for decreasing the viscosity, and 1 for decreasing the minimum temperature.

In formula (5), P¹, P² and P³ are independently a polymerizable group. Preferred P¹, P² or P³ is a polymerizable group selected from the group of groups represented by formula (P-1) to formula (P-6). Further, preferred P¹, P² or P³ is a group represented by formula (P-1), formula (P-2) or formula (P-3). Particularly preferred P¹, P² or P³ is a group represented by formula (P-1) or formula (P-2). Most preferred P¹, P² or P³ is a group represented by formula (P-1). The preferred group represented by formula (P-1) is —OCO—CH═CH₂ or —OCO—C(CH₃)═CH₂. A wavy line in formula (P-1) to formula (P-6) represents a site with which a bonding is formed.

In formula (P-1) to formula (P-6), M¹, M² and M³ are independently hydrogen, fluorine, alkyl having 1 to 5 carbons, or alkyl having 1 to 5 carbons in which at least one of hydrogen is replaced by fluorine or chlorine. Preferred M¹, M² or M³ is hydrogen or methyl for increasing reactivity. Further preferred M¹ is hydrogen or methyl, and further preferred M² or M³ is hydrogen.

Sp¹, Sp² and Sp³ are independently a single bond or alkylene having 1 to 10 carbons, and in the alkylene, at least one of —CH₂— may be replaced by —O—, —COO—, —OCO— or —OCOO—, at least one of —CH₂—CH₂— may be replaced by —CH═CH— or —C≡C—, and in the groups, at least one of hydrogen may be replaced by fluorine or chlorine. Preferred Sp¹, Sp² or Sp³ is a single bond, —CH₂CH₂—, —CH₂O—, —OCH₂—, —COO—, —OCO—, —CO—CH═CH— or —CH═CH—. Further preferred Sp¹, Sp² or Sp³ is a single bond.

When all of h pieces of P¹ and k pieces of P³ are a group represented by formula (P-4) in formula (5), at least one of h pieces of Sp¹ and k pieces of Sp³ is alkylene having 1 to 10 carbons in which at least one of —CH₂— is replaced by —O—, —COO—, —OCO— or —OCOO—.

Ring K and ring M are independently cyclohexyl, cyclohexenyl, phenyl, 1-naphthyl, 2-naphthyl, tetrahydropyran-2-yl, 1,3-dioxane-2-yl, pyrimidine-2-yl or pyridine-2-yl, and in the rings, at least one of hydrogen may be replaced by fluorine, chlorine, alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkyl having 1 to 12 carbons in which at least one of hydrogen is replaced by fluorine or chlorine. Preferred ring K or ring M is phenyl. Ring L is 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, naphthalene-1,2-diyl, naphthalene-1,3-diyl, naphthalene-1,4-diyl, naphthalene-1,5-diyl, naphthalene-1,6-diyl, naphthalene-1,7-diyl, naphthalene-1,8-diyl, naphthalene-2,3-diyl, naphthalene-2,6-diyl, naphthalene-2,7-diyl, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl or pyridine-2,5-diyl, and in the rings, at least one of hydrogen may be replaced by fluorine, chlorine, alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkyl having 1 to 12 carbons in which at least one of hydrogen is replaced by fluorine or chlorine. Preferred ring L is 1,4-phenylene or 2-fluoro-1,4-phenylene.

Z⁶ and Z⁷ are independently a single bond or alkylene having 1 to 10 carbons, and in the alkylene, at least one of —CH₂— may be replaced by —O—, —CO—, —COO— or —OCO—, at least one of —CH₂—CH₂— may be replaced by —CH═CH—, —C(CH₃)═CH—, —CH═C(CH₃)— or —C(CH₃)═C(CH₃)—, and in the groups, at least one of hydrogen may be replaced by fluorine or chlorine. Preferred Z⁶ or Z⁷ is a single bond, —CH₂CH₂—, —CH₂O—, —OCH₂—, —COO— or —OCO—. Further preferred Z⁶ or Z⁷ is a single bond.

Then, g is 0, 1, or 2. Preferred g is 0 or 1. Further, h, j and k are independently 0, 1, 2, 3 or 4, and a sum of h, j and k is 1 or more. Preferred h, j or k is 1 or 2.

Fifth, the preferred specific examples of the component compounds will be shown. Preferred compound (1) includes compound (1-1) to compound (1-7) described in item 2. In the compounds, at least one of the first components preferably includes compound (1-1), compound (1-3), compound (1-4) or compound (1-6). At least two of the first components preferably includes a combination of compound (1-1) and compound (1-4), a combination of compound (1-1) and compound (1-6), a combination of compound (1-1) and compound (1-7), a combination of compound (1-3) and compound (1-4), a combination of compound (1-3) and compound (1-6) or a combination of compound (1-3) and compound (1-7).

Preferred compound (3) includes compound (3-1) to compound (3-12) described in item 5. In the compounds, at least one of the third components preferably includes compound (3-2), compound (3-4), compound (3-5) or compound (3-6). At least two of the third components preferably includes a combination of compound (3-2) and compound (3-4) or a combination of compound (3-2) and compound (3-6).

Preferred compound (4) includes compound (4-1) to compound (4-19) described in item 8. In the compounds, at least one of the fourth components preferably includes compound (4-1), compound (4-2), compound (4-3), compound (4-4), compound (4-6) compound (4-7), compound (4-8) or compound (4-10). At least two of the fourth components preferably includes a combination of compound (4-1) and compound (4-6), a combination of compound (4-1) and compound (4-10), a combination of compound (4-3) and compound (4-6), a combination of compound (4-3) and compound (4-10), a combination of compound (4-4) and compound (4-6) or a combination of compound (4-4) and compound (4-10).

Preferred compound (5) includes compound (5-1) to compound (5-27) described in item 12. In the compounds, at least one of the additive components preferably includes compound (5-1), compound (5-2), compound (5-24), compound (5-25), compound (5-26) or compound (5-27). At least two of the additive components preferably includes a combination of compound (5-1) and compound (5-2), a combination of compound (5-1) and compound (5-18), a combination of compound (5-2) and compound (5-24), a combination of compound (5-2) and compound (5-25), a combination of compound (5-2) and compound (5-26), a combination of compound (5-25) and compound (5-26) or a combination of compound (5-18) and compound (5-24).

Sixth, the additive that may be added to the composition will be described. The additive is the optically active compound, the antioxidant, the ultraviolet light absorber, the dye, the antifoaming agent, the polymerizable compound, the polymerization initiator, the polymerization inhibitor or the like. The optically active compound is added to the composition for inducing a helical structure in a liquid crystal molecule to give a twist angle. Specific examples of such a compound include compound (6-1) to compound (6-5). A preferred ratio of the optically active compound is approximately 5% by weight or less. A further preferred ratio is in the range of approximately 0.01% by weight to approximately 2% by weight.

The antioxidant is added to the composition for preventing a decrease in the specific resistance caused by heating in air, or for maintaining a large voltage holding ratio at room temperature and also at the temperature close to the maximum temperature of the nematic phase after the device has been used for a long period of time. Preferred examples of the antioxidant include compound (7) where n is an integer from 1 to 9.

In compound (7), preferred n is 1, 3, 5, 7 or 9. Further preferred n is 7. Compound (7) where n is 7 is effective for maintaining the large voltage holding ratio at room temperature and also at the temperature close to the maximum temperature of the nematic phase even after the device has been used for a long period of time, because the compound (7) has a small volatility. A preferred ratio of the antioxidant is approximately 50 ppm or more for achieving the effect thereof, and approximately 600 ppm or less for avoiding a decrease in the maximum temperature or avoiding an increase in the minimum temperature. A further preferred ratio is in the range of approximately 100 ppm to approximately 300 ppm.

Preferred examples of the ultraviolet light absorber include a benzophenone derivative, a benzoate derivative and a triazole derivative. A light stabilizer such as an amine having steric hindrance is also preferred. A preferred ratio of the ultraviolet light absorber or the stabilizer is approximately 50 ppm or more for achieving the effect thereof, and approximately 10,000 ppm or less for avoiding a decrease in the maximum temperature or avoiding an increase in the minimum temperature. A further preferred ratio is in the range of approximately 100 ppm to approximately 10,000 ppm.

A dichroic dye such as an azo dye or an anthraquinone dye is added to the composition for the purpose of adapting the composition to a device having a guest host (GH) mode. A preferred ratio of the dye is in the range of approximately 0.01% by weight to approximately 10% by weight. An antifoaming agent such as dimethyl silicone oil or methyl phenyl silicone oil is added to the composition for preventing foam formation. A preferred ratio of the antifoaming agent is approximately 1 ppm or more for achieving the effect thereof, and approximately 1,000 ppm or less for avoiding a poor display. A further preferred ratio is in the range of approximately 1 ppm to approximately 500 ppm.

The polymerizable compound is used for the composition for the purpose of adapting the composition to a device having the polymer sustained alignment (PSA) mode. Compound (5) is suitable for the purpose. A polymerizable compound different from compound (5) may be added to the composition together with compound (5). Instead of compound (5), a polymerizable compound different from compound (5) may be added to the composition. Preferred examples of such a polymerizable compound include a compound such as acrylate, methacrylate, a vinyl compound, a vinyloxy compound, propenyl ether, an epoxy compound (oxirane, oxetane) and vinyl ketone. Further preferred examples include an acrylate derivative or a methacrylate derivative. A preferred ratio of compound (5) is approximately 10% by weight or more based on the total weight of the polymerizable compound. A further preferred ratio is approximately 50% by weight or more based thereon. A particularly preferred ratio is approximately 80% by weight or more based thereon. A most desirable ratio is 100% by weight.

The polymerizable compound such as compound (5) is polymerized by irradiation with ultraviolet light. The polymerizable compound may be polymerized in the presence of a suitable initiator such as a photopolymerization initiator. Suitable conditions for polymerization, suitable types of the initiator and suitable amounts thereof are known to a person skilled in the art and are described in literatures. For example, Irgacure 651 (registered trademark; BASF), Irgacure 184 (registered trademark; BASF) or Darocur 1173 (registered trademark; BASF), each being a photopolymerization initiator, is suitable for radical polymerization. A preferred ratio of the photopolymerization initiator is in the range of approximately 0.1% by weight to approximately 5% by weight based on the total weight of the polymerizable compound. A further preferred ratio is in the range of approximately 1% by weight to approximately 3% by weight based thereon.

Upon storing the polymerizable compound such as compound (5), the polymerization inhibitor may be added thereto for preventing polymerization. The polymerizable compound is ordinarily added to the composition without removing the polymerization inhibitor. Examples of the polymerization inhibitor include hydroquinone and a hydroquinone derivative such as methylhydroquinone, 4-tert-butylcatechol, 4-methoxyphenol or phenothiazine.

Seventh, the method for synthesizing the component compound will be described. The compound can be prepared according to a known method. Examples of synthetic methods will be shown. Compound (1-1) is prepared by the method described in JP 2008-545671 A. Compound (2) is prepared by the method described in JP S59-176221 A. Compound (3-1) is prepared by the method described in JP S56-68636 A. Compound (4-1) is prepared by the method described in JP H2-503441 A. Compound (5-18) is prepared by the method described in JP H7-101900 A. A compound represented by formula (7) where n is 1 is available from Sigma-Aldrich Corporation. Compound (7) where n is 7 and so forth is prepared according to the method described in U.S. Pat. No. 3,660,505 B.

Any compounds whose synthetic methods are not described above can be prepared according to the methods described in books such as Organic Syntheses (John Wiley & Sons, Inc.), Organic Reactions (John Wiley & Sons, Inc.), Comprehensive Organic Synthesis (Pergamon Press) and New Experimental Chemistry Course (Shin Jikken Kagaku Koza in Japanese) (Maruzen Co., Ltd.). The composition is prepared according to publicly known methods using the thus obtained compounds. For example, the component compounds are mixed and dissolved in each other by heating.

Last, the application of the composition will be described. Most of the compositions have a minimum temperature of approximately −10° C. or lower, a maximum temperature of approximately 70° C. or higher, and an optical anisotropy in the range of approximately 0.07 to approximately 0.20. A composition having an optical anisotropy in the range of approximately 0.08 to approximately 0.25 may be prepared by controlling the ratio of the component compounds or by mixing with any other liquid crystal compound. A composition having an optical anisotropy in the range of approximately 0.10 to approximately 0.30 may be prepared by the method. The device containing the composition has a large voltage holding ratio. The composition is suitable for use in the AM device. The composition is particularly suitable for use in a transmissive AM device. The composition can be used as the composition having the nematic phase and as the optically active composition by adding the optically active compound.

The composition can be used for the AM device. The composition can also be used for a PM device. The composition can also be used for the AM device and the PM device each having a mode such as the PC mode, the TN mode, the STN mode, the ECB mode, the OCB mode, the IPS mode, the FFS mode, the VA mode and the FPA mode. Use for an AM device having the TN, OCB, IPS or FFS mode is particularly preferred. In an AM device having the IPS mode or FFS mode, alignment of liquid crystal molecules in a state in which no voltage is applied may be parallel or perpendicular to a glass substrate. The devices may be of a reflective type, a transmissive type or a transflective type. Use for the transmissive device is preferred. The composition can also be used for an amorphous silicon-TFT device or a polycrystal silicon-TFT device. The composition can also be used for a nematic curvilinear aligned phase (NCAP) device prepared by microencapsulating the composition, and for a polymer dispersed (PD) device in which a three-dimensional network-polymer is formed in the composition.

It will be apparent to those skilled in the art that various modifications and variations can be made in the invention and specific examples provided herein without departing from the spirit or scope of the invention. Thus, it is intended that the invention covers the modifications and variations of this invention that come within the scope of any claims and their equivalents.

The following examples are for illustrative purposes only and are not intended, nor should they be interpreted to, limit the scope of the invention.

EXAMPLES

The invention will be described in greater detail by way of Examples. However, the invention is not limited by the Examples. The invention includes a mixture of a composition in Example 1 and a composition in Example 2. The invention also includes a mixture in which at least two compositions in Examples are mixed. A prepared compound was identified by a method such as NMR analysis. Characteristics of the compound, the composition and the device were measured by methods described below.

NMR analysis: For measurement, DRX-500 made by Bruker BioSpin Corporation was used. In ¹H-NMR measurement, a sample was dissolved in a deuterated solvent such as CDCl₃, and measurement was carried out under conditions of room temperature, 500 MHz and 16 times of accumulation. Tetramethylsilane was used as an internal standard. In ¹⁹F-NMR measurement, measurement was carried out under conditions of 24 times of accumulation using CFCl₃ as an internal standard. In the explanation of nuclear magnetic resonance spectra, s, d, t, q, quin, sex, m stand for a singlet, a doublet, a triplet, a quartet, a quintet, a sextet and a multiplet, respectively, and br means broad.

Gas chromatographic analysis: GC-14B Gas Chromatograph made by Shimadzu Corporation was used for measurement. A carrier gas was helium (2 mL per minute). A sample injector and a detector (FID) were set to 280° C. and 300° C., respectively. A capillary column DB-1 (length 30 m, bore 0.32 mm, film thickness 0.25 μm; dimethylpolysiloxane as a stationary phase, non-polar) made by Agilent Technologies, Inc. was used for separation of component compounds. After the column was kept at 200° C. for 2 minutes, the column was heated to 280° C. at a rate of 5° C. per minute. A sample was prepared in an acetone solution (0.1% by weight), and then 1 microliter of the solution was injected into the sample injector. A recorder was C-R5A Chromatopac made by Shimadzu Corporation or an equivalent thereof. The resulting chromatogram showed a retention time of a peak and a peak area corresponding to each of the component compounds.

As a solvent for diluting the sample, chloroform, hexane and so forth may also be used. The following capillary columns may also be used for separating the component compounds: HP-1 (length 30 m, bore 0.32 mm, film thickness 0.25 μm) made by Agilent Technologies, Inc., Rtx-1 (length 30 m, bore 0.32 mm, film thickness 0.25 μm) made by Restek Corporation and BP-1 (length 30 m, bore 0.32 mm, film thickness 0.25 μm) made by SGE International Pty. Ltd. A capillary column CBP1-M50-025 (length 50 m, bore 0.25 mm, film thickness 0.25 μm) made by Shimadzu Corporation may also be used for the purpose of avoiding an overlap of peaks of the compounds.

A ratio of liquid crystal compounds included in the composition may be calculated by the method as described below. The mixture of liquid crystal compounds is detected by gas chromatograph (FID). An area ratio of each peak in the gas chromatogram corresponds to the ratio (weight ratio) of the liquid crystal compound. When the capillary columns described above were used, a correction coefficient of each of the liquid crystal compounds may be regarded as 1 (one). Accordingly, the ratio (% by weight) of the liquid crystal compound is calculated from the area ratio of each peak.

Sample for measurement: When characteristics of a composition and a device were measured, the composition was used as a sample as was. Upon measuring characteristics of a compound, a sample for measurement was prepared by mixing the compound (15% by weight) with a base liquid crystal (85% by weight). Values of characteristics of the compound were calculated using values obtained by measurement, according to an extrapolation method: (Extrapolated value)={(measured value of a sample for measurement)−0.85×(measured value of a base liquid crystal)}/0.15. When a smectic phase (or crystals) precipitated at the ratio thereof at 25° C., a ratio of the compound to the base liquid crystals was changed step by step in the order of (10% by weight:90% by weight), (5% by weight:95% by weight) and (1% by weight:99% by weight). Values of a maximum temperature, an optical anisotropy, viscosity and a dielectric anisotropy with regard to the compound were determined according to the extrapolation method.

A base liquid crystal described below was used. A ratio of the component compound was expressed in terms of weight percent (% by weight).

Measuring method: Measurement of characteristics was carried out by the methods described below. Most of the measurement methods are applied as described in the Standard of the Japan Electronics and Information Technology Industries Association (hereinafter, abbreviated as JEITA) (JEITA ED-2521B) discussed and established by JEITA, or modified thereon. No thin film transistor (TFT) was attached to a TN device used for measurement.

(1) Maximum temperature of nematic phase (NI; ° C.): A sample was placed on a hot plate in a melting point apparatus equipped with a polarizing microscope, and heated at a rate of 1° C. per minute. Temperature when a part of the sample began to change from a nematic phase to an isotropic liquid was measured. A higher limit of a temperature range of the nematic phase may be abbreviated as “maximum temperature.”

(2) Minimum temperature of nematic phase (T_(c); ° C.): Samples each having a nematic phase were put in glass vials and kept in freezers at temperatures of 0° C., −10° C., −20° C., −30° C. and −40° C. for 10 days, and then liquid crystal phases were observed. For example, when the sample maintained the nematic phase at −20° C. and changed to crystals or a smectic phase at −30° C., T_(c) was expressed as T_(c)<−20° C. A lower limit of the temperature range of the nematic phase may be abbreviated as “minimum temperature.”

(3) Viscosity (bulk viscosity; η; measured at 20° C.; mPa·s): A cone-plate (E type) rotational viscometer made by Tokyo Keiki, Inc. was used for measurement.

(4) Viscosity (rotational viscosity; γ1; measured at 25° C.; mPa·s): Measurement was carried out according to a method described in M. Imai et al., Molecular Crystals and Liquid Crystals, Vol. 259, p. 37 (1995). A sample was put in a VA device in which a distance (cell gap) between two glass substrates was 20 micrometers. Voltage was applied stepwise to the device in the range of 39 V to 50 V at an increment of 1 V. After a period of 0.2 second with no voltage, a voltage was applied repeatedly under the conditions of only one rectangular wave (rectangular pulse; 0.2 second) and no voltage (2 seconds). A peak current and a peak time of a transient current generated by the applied voltage were measured. A value of rotational viscosity was obtained from the measured values and a calculation equation (8) described on page 40 of the paper presented by M. Imai et al. A dielectric anisotropy required for the calculation was measured according to section (6).

(5) Optical anisotropy (refractive index anisotropy; An; measured at 25° C.): Measurement was carried out by an Abbe refractometer with a polarizing plate mounted on an ocular, using light at a wavelength of 589 nanometers. A surface of a main prism was rubbed in one direction, and then a sample was added dropwise onto the main prism. A refractive index (n∥) was measured when the direction of polarized light was parallel to the direction of rubbing. A refractive index (n⊥) was measured when the direction of polarized light was perpendicular to the direction of rubbing. A value of optical anisotropy was calculated from an equation: Δn=n∥−n⊥.

(6) Dielectric anisotropy (Δε; measured at 25° C.): A value of dielectric anisotropy was calculated from an equation: Δε=ε∥−ε⊥. Dielectric constants (ε∥ and ε⊥) were measured as described below.

(6-1) Measurement of dielectric constant (ε∥): An ethanol (20 mL) solution of octadecyl triethoxysilane (0.16 mL) was applied to a well-washed glass substrate. After rotating the glass substrate with a spinner, the glass substrate was heated at 150° C. for 1 hour. A sample was put in a VA device in which a distance (cell gap) between two glass substrates was 4 micrometers, and the device was sealed with an ultraviolet-curable adhesive. Sine waves (0.5 V, 1 kHz) were applied to the device, and after 2 seconds, a dielectric constant (d) in the major axis direction of liquid crystal molecules was measured.

(6-2) Measurement of dielectric constant (ε⊥): A polyimide solution was applied to a well-washed glass substrate. After calcining the glass substrate, rubbing treatment was applied to the alignment film obtained. A sample was put in a TN device in which a distance (cell gap) between two glass substrates was 9 micrometers and a twist angle was 80 degrees. Sine waves (0.5 V, 1 kHz) were applied to the device, and after 2 seconds, a dielectric constant (ε⊥) in the minor axis direction of the liquid crystal molecules was measured.

(7) Threshold voltage (Vth; measured at 25° C.; V): An LCD-5100 luminance meter made by Otsuka Electronics Co., Ltd. was used for measurement. A light source was a halogen lamp. A sample was put in a normally black mode VA device in which a distance (cell gap) between two glass substrates was 4 micrometers and a rubbing direction was anti-parallel, and the device was sealed with an ultraviolet-curable adhesive. A voltage (60 Hz, rectangular waves) to be applied to the device was stepwise increased from 0 V to 20 V at an increment of 0.02 V. On the occasion, the device was irradiated with light from a direction perpendicular to the device, and the amount of light passing through the device was measured. A voltage-transmittance curve was prepared, in which the maximum amount of light corresponds to 100% transmittance and the minimum amount of light corresponds to 0% transmittance. A threshold voltage is expressed in terms of a voltage at 10% transmittance.

(8) Voltage holding ratio (VHR-1; measured at 25° C.; %): A TN device used for measurement had a polyimide alignment film, and a distance (cell gap) between two glass substrates was 5 micrometers. A sample was put in the device, and then the device was sealed with an ultraviolet-curable adhesive. A pulse voltage (60 microseconds at 5 V) was applied to the TN device and the device was charged. A decaying voltage was measured for 16.7 milliseconds with a high-speed voltmeter, and area A between a voltage curve and a horizontal axis in a unit cycle was obtained. Area B is an area without decay. A voltage holding ratio is expressed in terms of a percentage of area A to area B.

(9) Voltage holding ratio (VHR-2; measured at 80° C.; %): A voltage holding ratio was measured according to procedures identical with the procedures described above except that measurement was carried out at 80° C. in place of 25° C. The thus obtained value was expressed in terms of VHR-2.

(10) Voltage holding ratio (VHR-3; measured at 25° C.; %: Stability to ultraviolet light was evaluated by measuring a voltage holding ratio after a device was irradiated with ultraviolet light. A TN device used for measurement had a polyimide alignment film and a cell gap was 5 micrometers. A sample was injected into the device, and then the device was irradiated with light for 20 minutes. A light source was an ultrahigh-pressure mercury lamp USH-500D (made by Ushio, Inc.), and a distance between the device and the light source was 20 centimeters. In measurement of VHR-3, a decaying voltage was measured for 16.7 milliseconds. A composition having a large VHR-3 has a large stability to ultraviolet light. A value of VHR-3 is preferably 90% or more, further preferably, 95% or more.

(11) Voltage holding ratio (VHR-4; measured at 25° C.; %): A TN device into which a sample was injected was heated in a constant-temperature bath at 80° C. for 500 hours, and then stability to heat was evaluated by measuring a voltage holding ratio. In measurement of VHR-4, a decaying voltage was measured for 16.7 milliseconds. A composition having a large VHR-4 has a large stability to heat.

(12) Response time (i; measured at 25° C.; ms): An LCD-5100 luminance meter made by Otsuka Electronics Co., Ltd. was used for measurement. A light source was a halogen lamp. A low-pass filter was set at 5 kHz. A sample was put in a normally black mode VA device in which a distance (cell gap) between two glass substrates was 4 micrometers and a rubbing direction was anti-parallel. The device was sealed with an ultraviolet-curable adhesive. Rectangular waves (60 Hz, 10 V, 0.5 second) were applied to the device. On the occasion, the device was irradiated with light from a direction perpendicular to the device, and the amount of light passing through the device was measured. A voltage-transmittance curve was prepared, in which the maximum amount of light corresponds to 100% transmittance and the minimum amount of light corresponds to 0% transmittance. A response time was expressed in terms of time required for a change from 90% transmittance to 10% transmittance (fall time; millisecond).

(13) Specific resistance (p; measured at 25° C.; Ωcm): Into a vessel equipped with electrodes, 1.0 mL of a sample was injected. A DC voltage (10 V) was applied to the vessel, and a DC current after 10 seconds was measured. A specific resistance was calculated from the following equation: (specific resistance)={(voltage)×(electric capacity of a vessel)}/{(direct current)×(dielectric constant of vacuum)}.

Compounds described in Examples were expressed using symbols according to definitions in Table 3 below. In Table 3, a configuration of 1,4-cyclohexylene is trans. A parenthesized number next to a symbolized compound in Examples corresponds to the number of the compound. A symbol (-) means any other liquid crystal compound. A ratio (percentage) of the liquid crystal compound is expressed in terms of weight percent (% by weight) based on the weight of the liquid crystal composition. Last, values of characteristics of the composition were summarized.

TABLE 3 Method for Description of Compounds using Symbols R—(A₁)—Z₁— . . . —Z_(n)—(A_(n))—R′ 1) Left-terminal Group R— Symbol FC_(n)H_(2n)— Fn- C_(n)H_(2n+1)— n- C_(n)H_(2n+1)O— nO— C_(m)H_(2m+1)OC_(n)H_(2n)— mOn- CH₂═CH— V— C_(n)H_(2n+1)—CH═CH— nV— CH₂═CH—C_(n)H_(2n)— Vn- C_(m)H_(2m+1)—C═CH—C_(n)H_(2n)— mVn- CF₂═CH— VFF— CF₂═CH—C_(n)H_(2n)— VFFn- C_(m)H_(2m+1)CF₂C_(n)H_(2n)— m(CF2)n- CH₂═CHCOO— AC— CH_(2═)C(CH₃)COO— MAC— 2) Right-terminal Group —R′ Symbol —C_(n)H_(2n+1) -n —OC_(n)H_(2n+1) —On —CH═CH₂ —V —CH═CH—C_(n)H_(2n+1) —Vn —C_(n)H_(2n)—CH═CH₂ -nV —C_(m)H_(2m)—CH═C_(n)H_(2n+1) -mVn —CH═CF₂ —VFF —OCOCH═CH₂ —AC —OCOC(CH₃)═CH₂ —MAC 3) Bonding Group —Z_(n)— Symbol —C_(n)H_(2n)— n —COO— E —CH═CH— V —CH═CHO— VO —OCH═CH— OV —CH₂O— 1O —OCH₂— O1 4) Ring Structure —A_(n)— Symbol

H

B

B(F)

B(2F)

B(2F,5F)

B(2F,3F)

B(2F,3Cl)

dh

Dh

dPR

DPR

Cro(7F,8F)

ch 5) Example of Description

Example 1

3-HDPRB(2F,3F)—O2 (1-4)  5% 5-HDPRB(2F,3F)—O2 (1-4)  5% 3-HH—V (2) 24% 1-BB-3 (3-2)  3% 3-HB(2F,3F)—O2 (4-1) 14% 3-BB(2F,3F)—O2 (4-4) 10% 2-HHB(2F,3F)—O2 (4-6)  6% 3-HHB(2F,3F)—O2 (4-6) 10% 4-HHB(2F,3F)—O2 (4-6) 10% 2-HBB(2F,3F)—O2 (4-10)  3% 3-HBB(2F,3F)—O2 (4-10) 10%

NI=81.4° C.; Tc<−20° C.; η=21.5 mPa·s; Δn=0.108; Δε=−4.5; Vth=1.88 V; γ1=125.9 mPa·s.

Comparative Example 1

The composition in Example 1 contains compound (1) being the first component. Compound (1) has a negative dielectric anisotropy. Compound (4) also has a negative dielectric anisotropy. For comparison, a composition in which two compounds being the first components in Example 1 were replaced by compounds (4) similar thereto, respetrively, was taken as Comparative Example 1.

3-HchB(2F,3F)—O2 (4-19)  5% 5-HchB(2F,3F)—O2 (4-19)  5% 3-HH—V (2) 24% 1-BB-3 (3-2)  3% 3-HB(2F,3F)—O2 (4-1) 14% 3-BB(2F,3F)—O2 (4-4) 10% 2-HHB(2F,3F)—O2 (4-6)  6% 3-HHB(2F,3F)—O2 (4-6) 10% 4-HHB(2F,3F)—O2 (4-6) 10% 2-HBB(2F,3F)—O2 (4-10)  3% 3-HBB(2F,3F)—O2 (4-10) 10%

NI=84.9° C.; Δn=0.107; Δε=−3.9; Vth=2.06 V.

Example 2

3-DPRB(2F,3F)—O2 (1-1)  4% 5-DPRB(2F,3F)—O2 (1-1)  4% 3-DPR1OB(2F,3F)—O2 (1-3)  4% 3-HDPRB(2F,3F)—O2 (1-4)  4% 5-HDPRB(2F,3F)—O2 (1-4)  4% 3-HH—V (2) 15% 3-HH—V1 (2) 10% 3-HB—O2 (3-1)  3% 3-HHEH-3 (3-3)  5% 3-H2B(2F,3F)—O2 (4-2)  3% 5-H2B(2F,3F)—O2 (4-2)  3% 3-BB(2F,3F)—O2 (4-4) 10% 3-HHB(2F,3F)—O2 (4-6) 10% 4-HHB(2F,3F)—O2 (4-6) 10% 3-HBB(2F,3F)—O2 (4-10)  8% V2-HchB(2F,3F)—O2 (4-19)  3%

NI=83.1° C.; Tc<−20° C.; η=20.6 mPa·s; Δn=0.106; Δε=−4.6; Vth=1.89 V; γ1=120.4 mPa·s.

Example 3

3-HDPRB(2F,3F)—O2 (1-4)  5% 5-HDPRB(2F,3F)—O2 (1-4)  5% 3-HDPR2B(2F,3F)—O2 (1-5)  4% 5-HDPR2B(2F,3F)—O2 (1-5)  3% 2-HH-5 (2)  4% 3-HH-4 (2)  3% 3-HH—O1 (2)  3% 3-HH—V (2) 10% 3-HH—V1 (2)  7% 3-HB—O2 (3-1)  3% V-HHB-1 (3-4)  3% 3-HB(2F,3F)—O2 (4-1)  6% 5-HB(2F,3F)—O2 (4-1)  8% 5-H2B(2F,3F)—O2 (4-2)  3% 3-B(2F,3F)B(2F,3F)—O2 (4-5)  3% 2-HHB(2F,3F)—O2 (4-6)  8% 3-HHB(2F,3F)—O2 (4-6)  9% 2-HBB(2F,3F)—O2 (4-10)  3% 3-HBB(2F,3F)—O2 (4-10) 10%

NI=86.6° C.; Tc<−20° C.; η=22.4 mPa·; Δn=0.102; Δε=−4.4; Vth=1.92 V; γ1=131.0 mPa·s.

Example 4

3-DPR1OB(2F,3F)—O2 (1-3) 3% 5-DPR1OB(2F,3F)—O2 (1-3) 3% 3-HDPRB(2F,3F)—O2 (1-4) 5% 3-HDPR2B(2F,3F)—O2 (1-5) 5% 2-HH-3 (2) 16%  3-HH—O1 (2) 4% 5-HH—O1 (2) 5% 2-BB(F)B—2V (3-6) 3% 3-HHEBH-3 (3-9) 4% V—HB(2F,3F)—O2 (4-1) 3% 3-HB(2F,3F)—O2 (4-1) 10%  3-H1OB(2F,3F)—O2 (4-3) 4% 3-BB(2F,3F)—O (4-4) 10%  3-HHB(2F,3F)—O2 (4-6) 5% V—HHB(2F,3F)—O2 (4-6) 5% 3-HH1OB(2F,3F)—O2 (4-8) 5% 3-HBB(2F,3F)—O2 (4-10) 10%

NI=74.0° C.; Tc<−20° C.; η=22.4 mPa·s; Δn=0.105; Δε=−4.9; Vth=1.82 V; γ1=131.0 mPa·s.

Example 5

5-DPRB(2F,3F)—O2 (1-1) 4% 3-HDPRB(2F,3F)—O2 (1-4) 5% 5-HDPRB(2F,3F)—O2 (1-4) 3% 3-HDPR1OB(2F,3F)—O2 (1-6) 4% 5-HDPR1OB(2F,3F)—O2 (1-6) 3% 1V2—HH—2V1 (2) 3% 3-HH—V (2) 15%  3-HH—V1 (2) 12%  1-BB-5 (3-2) 3% 5-B(F)BB-2 (3-7) 3% 3-HB(F)HH-2 (3-8) 2% 3-HB(2F,3F)—O2 (4-1) 8% 2-HHB(2F,3F)—O2 (4-6) 6% 3-HHB(2F,3F)—O2 (4-6) 10%  3-HH2B(2F,3F)—O2 (4-7) 3% 3-HBB(2F,3F)—O2 (4-10) 6% 3-HEB(2F,3F)B(2F,3F)—O2 (4-11) 3% 3-HDhB(2F,3F)—O2 (4-16) 7%

NI=97.3° C.; Tc<−20° C.; η=23.1 mPa·s; Δn=0.110; Δε=−4.4; Vth=1.94 V; γ1=135.2 mPa·s.

Example 6

3-DDRB(2F,3F)—O2 (1-1) 5% 3-DPR2B(2F,3F)—O2 (1-2) 3% 3-HDPRB(2F,3F)—O2 (1-4) 5% 5-HDPR1OB(2F,3F)—O2 (1-6) 3% 3-dPRBB(2F,3F)—O2 (1-7) 3% 3-HH—V (2) 17%  3-HH—V1 (2) 10%  F3—HH—V (2) 3% VFF—HHB-1 (3-4) 3% 3-HB(2F,3F)—O2 (4-1) 12%  3-BB(2F,3F)—O2 (4-4) 10%  3-HHB(2F,3F)—O2 (4-6) 10%  V—HHB(2F,3F)—O2 (4-6) 10%  4-HBB(2F,3F)—O2 (4-10) 3% 3-HH1OCro(7F,8F)-5 (4-15) 3%

NI=74.3° C.; Tc<−20° C.; η=18.8 mPa·s; Δn=0.103; Δε=−4.4; Vth=1.90 V; γ1=110.1 mPa·s.

Example 7

5-DPRB(2F,3F)—O2 (1-1) 5% 3-DPR1OB(2F,3F)—O2 (1-3) 3% 3-HDPRB(2F,3F)—O2 (1-4) 5% 3-HDPR1OB(2F,3F)—O2 (1-6) 4% 2-HH-3 (2) 12%  2-HH-5 (2) 12%  3-HH—VFF (2) 3% V2—BB-1 (3-2) 3% 3-HHB—O1 (3-4) 3% 3-HB(2F,3F)—O2 (4-1) 9% 5-HB(2F,3F)—O2 (4-1) 7% 3-HHB(2F,3F)—O2 (4-6) 10%  4-HHB(2F,3F)—O2 (4-6) 8% 3-HBB(2F,3F)—O2 (4-10) 11%  3-HBB(2F,3Cl)—O2 (4-13) 5%

NI=82.1° C.; Tc<−20° C.; η=23.3 mPa·s; Δn=0.101; Δε=−4.5; Vth=1.88 V; γ1=136.3 mPa·s.

Example 8

3-HDPRB(2F,3F)—O2 (1-4) 5% 5-HDPRB(2F,3F)—O2 (1-4) 4% 3-HDPR1OB(2F,3F)—O2 (1-6) 4% 3-HH—V (2) 15%  5-HH—V (2) 8% 3-HH—V1 (2) 5% 1-BB-3 (3-2) 3% 5-HBB(F)B-3 (3-12) 3% 3-HB(2F,3F)—O2 (4-1) 9% 5-HB(2F,3F)—O2 (4-1) 10%  V—HHB(2F,3F)—O2 (4-6) 10%  3-HBB(2F,3F)—O2 (4-10) 10%  5-HBB(2F,3F)—O2 (4-10) 6% 3-HDhB(2F,3F)—O2 (4-16) 5% 1O1—HBBH-5 (−) 3%

NI=93.5° C.; Tc<−20° C.; η=22.8 mPa·s; Δn=0.110; Δε=−4.4; Vth=1.92 V; γ1=133.3 mPa·s.

Example 9

3-DDRB(2F,3F)—O2 (1-1) 5% 3-HDPRB(2F,3F)—O2 (1-4) 5% 3-HDPR1OB(2F,3F)—O2 (1-6) 3% 5-HDPR1OB(2F,3F)—O2 (1-6) 4% 2-HH-3 (2) 20%  3-HH-4 (2) 10%  1V2—BB-1 (3-2) 3% 5-HB(F)BH-3 (3-11) 3% 3-HB(2F,3F)—O2 (4-1) 13%  5-HH2B(2F,3F)—O2 (4-7) 4% V—HH1OB(2F,3F)—O2 (4-8) 10%  4-HBB(2F,3F)—O2 (4-10) 6% 3-HEB(2F,3F)B(2F,3F)—O2 (4-11) 3% 3-HHB(2F,3Cl)—O2 (4-12) 5% 3-HchB(2F,3F)—O2 (4-19) 3% 5-HchB(2F,3F)—O2 (4-19) 3%

NI=84.7° C.; Tc<−20° C.; η=23.7 mPa·s; Δn=0.097; Δε=−4.4; Vth=1.89 V; γ1=138.8 mPa·s.

Example 10

3-DPR2B(2F,3F)—O2 (1-2) 3% 3-DPR1OB(2F,3F)—O2 (1-3) 4% 3-HDPRB(2F,3F)—O2 (1-4) 5% 3-HDPR2B(2F,3F)—O2 (1-5) 5% 3-HH—V (2) 18%  3-HH—V1 (2) 12%  5-HB—O2 (3-1) 3% 3-HBB-2 (3-5) 3% 3-HB(2F,3F)—O2 (4-1) 8% 5-HB(2F,3F)—O2 (4-1) 6% 2O—BB(2F,3F)—O2 (4-4) 5% 2-HHB(2F,3F)—O2 (4-6) 6% 3-HHB(2F,3F)—O2 (4-6) 10%  3-HBB(2F,3F)—O2 (4-10) 12% 

NI=81.8° C.; Tc<−20° C.; η=17.8 mPa·s; Δn=0.106; Δε=−4.4; Vth=1.90 V; γ1=104.0 mPa·s.

Example 11

3-DPRB(2F,3F)—O2 (1-1) 4% 5-DPRB(2F,3F)—O2 (1-1) 3% 2-HH-3 (2) 9% 2-HH-5 (2) 4% 3-HH-4 (2) 5% 3-HH—V1 (2) 10%  7-HB-1 (3-1) 5% 2-BB(F)B-3 (3-6) 3% V—HB(2F,3F)—O2 (4-1) 4% 3-HB(2F,3F)—O2 (4-1) 10%  3-HHB(2F,3F)—O2 (4-6) 10%  V—HHB(2F,3F)—O2 (4-6) 10%  2-HH1OB(2F,3F)—O2 (4-8) 3% 3-HBB(2F,3F)—O2 (4-10) 8% 5-HBB(2F,3F)—O2 (4-10) 7% V—HBB(2F,3F)—O2 (4-10) 3% 3-chB(2F,3F)—O2 (4-18) 2%

NI=79.6° C.; Tc<−20° C.; η=19.8 mPa·s; Δn=0.104; Δε=−4.4; Vth=1.90 V; γ1=115.7 mPa·s.

Example 12

3-DPRB(2F,3F)—O2 (1-1) 3% 5-DPR1OB(2F,3F)—O2 (1-3) 5% 3-HDPRB(2F,3F)—O2 (1-4) 4% 5-HDPRB(2F,3F)—O2 (1-4) 3% 3-HH—V (2) 18%  3-HH—V1 (2) 13%  1-BB-5 (3-2) 3% 5-HB(2F,3F)—O2 (4-1) 13%  2-HHB(2F,3F)—O2 (4-6) 6% 3-HHB(2F,3F)—O2 (4-6) 10%  4-HHB(2F,3F)—O2 (4-6) 5% 2-BB(2F,3F)B-3 (4-9) 4% 2-HBB(2F,3F)—O2 (4-10) 3% 3-HBB(2F,3F)—O2 (4-10) 10% 

NI=83.9° C.; Tc<−20° C.; η=19.0 mPa·s; Δn=0.107; Δε=−4.4; Vth=1.88 V; γ1=111.3 mPa·s.

Example 13

3-DPRB(2F,3F)—O2 (1-1) 4% 5-DPRB(2F,3F)—O2 (1-1) 3% 3-HDPRB(2F,3F)—O2 (1-4) 4% 5-HDPRB(2F,3F)—O2 (1-4) 4% 5-dPRBB(2F,3F)—O2 (1-7) 3% 3-HH—V (2) 18%  5-HH—V (2) 4% 3-HH—V1 (2) 5% 3-HHB-1 (3-4) 3% 3-HB(2F,3F)—O2 (4-1) 13%  3-BB(2F,3F)—O2 (4-4) 10%  2-HHB(2F,3F)—O2 (4-6) 6% 3-HHB(2F,3F)—O2 (4-6) 10%  V—HBB(2F,3F)—O2 (4-10) 10%  5-HHB(2F,3Cl)—O2 (4-12) 3%

NI=76.3° C.; Tc<−20° C.; η=20.7 mPa·s; Δn=0.107; Δε=−4.4; Vth=1.87 V; γ1=121.1 mPa·s.

Example 14

3-DPR2B(2F,3F)—O2 (1-2) 5% 3-HDPRB(2F,3F)—O2 (1-4) 4% 5-HDPRB(2F,3F)—O2 (1-4) 5% 2-HH-3 (2) 6% 2-HH-5 (2) 7% 3-HH—V (2) 10%  3-HH—V1 (2) 5% V—HHB-1 (3-4) 3% V—HBB-3 (3-5) 3% 3-HB(2F,3F)—O2 (4-1) 10%  2-H1OB(2F,3F)—O2 (4-3) 3% 3-BB(2F,3F)—O2 (4-4) 5% 5-BB(2F,3F)—O2 (4-4) 5% V—HH1OB(2F,3F)—O2 (4-8) 3% 3-HBB(2F,3F)—O2 (4-10) 6% 5-HBB(2F,3F)—O2 (4-10) 6% 3-HEB(2F,3F)B(2F,3F)—O2 (4-11) 8% V-chB(2F,3F)—O2 (4-18) 3% 5-HchB(2F,3F)—O2 (4-19) 3%

NI=71.4° C.; Tc<−20° C.; η=22.1 mPa·s; Δn=0.109; Δε=−4.5; Vth=1.87 V; γ1=129.5 mPa·s.

Example 15

3-DPR2B(2F,3F)—O2 (1-2) 3% 3-DPR1OB(2F,3F)—O2 (1-3) 5% 5-DPR1OB(2F,3F)—O2 (1-3) 5% 3-HDPRB(2F,3F)—O2 (1-4) 4% 3-HH—V (2) 27%  3-HHEH-5 (3-3) 3% 5-HBBH-3 (3-10) 3% 3-HB(2F,3F)—O2 (4-1) 14%  3-HHB(2F,3F)—O2 (4-6) 10%  4-HHB(2F,3F)—O2 (4-6) 10%  2-HBB(2F,3F)—O2 (4-10) 3% 3-HBB(2F,3F)—O2 (4-10) 10%  3-dhBB(2F,3F)—O2 (4-17) 3%

NI=85.0° C.; Tc<−20° C.; η=21.5 mPa·s; Δn=0.101; Δε=−4.4; Vth=1.89 V; γ1=126.1 mPa·s.

Example 16

5-DPRB(2F,3F)—O2 (1-1) 3% 3-DPR1OB(2F,3F)—O2 (1-3) 3% 3-HDPRB(2F,3F)—O2 (1-4) 5% 3-HDPR1OB(2F,3F)—O2 (1-6) 3% 3-HH—V (2) 25%  3-HH—V1 (2) 8% 5-HBB(F)B-2 (3-12) 3% 3-HB(2F,3F)—O2 (4-1) 10%  5-BB(2F,3F)—O2 (4-4) 5% 3-HHB(2F,3F)—O2 (4-6) 10%  4-HHB(2F,3F)—O2 (4-6) 10%  3-HBB(2F,3F)—O2 (4-10) 5% 3-HEB(2F,3F)B(2F,3F)—O2 (4-11) 7% 5-HBB(2F,3Cl)—O2 (4-13) 3%

NI=88.7° C.; Tc<−20° C.; η=23.1 mPa·s; Δn=0.104; Δε=−4.4; Vth=1.90 V; γ1=135.1 mPa·s.

Example 17

5-DPR2B(2F,3F)—O2 (1-2) 3% 3-HDPRB(2F,3F)—O2 (1-4) 3% 5-HDPRB(2F,3F)—O2 (1-4) 3% 3-HDPR1OB(2F,3F)—O2 (1-6) 3% 5-HDPR1OB(2F,3F)—O2 (1-6) 3% 2-HH-5 (2) 8% 3-HH-4 (2) 8% 3-HH—V1 (2) 13%  V2—HHB-1 (3-4) 3% 3-HHEBH-4 (3-9) 3% 3-HB(2F,3F)—O2 (4-1) 14%  2-HHB(2F,3F)—O2 (4-6) 6% 3-HHB(2F,3F)—O2 (4-6) 10%  2-BB(2F,3F)B-4 (4-9) 3% 3-HBB(2F,3F)—O2 (4-10) 10%  3-HBB(2F,3Cl)—O2 (4-13) 3% 3-H10Cro(7F,8F)-5 (4-14) 4%

NI=95.9° C.; Tc<−20° C.; η=24.8 mPa·s; Δn=0.105; Δε=−4.4; Vth=1.91 V; γ1=145.2 mPa·s.

Example 18

5-DPRB(2F,3F)—O2 (1-1) 3% 3-HDPRB(2F,3F)—O2 (1-4) 4% 3-HDPR1OB(2F,3F)—O2 (1-6) 4% 5-HDPR1OB(2F,3F)—O2 (1-6) 4% 2-HH-3 (2) 7% 3-HH—O1 (2) 3% 3-HH—V (2) 10%  5-HH—V (2) 10%  3-HH—V1 (2) 10%  V—HBB-2 (3-5) 3% 5-HB(2F,3F)—O2 (4-1) 5% 2-H1OB(2F,3F)—O2 (4-3) 5% 3-H1OB(2F,3F)—O2 (4-3) 5% V—HHB(2F,3F)—O2 (4-6) 5% 3-HH1OB(2F,3F)—O2 (4-8) 5% 2-BB(2F,3F)B-3 (4-9) 3% 3-H10Cro(7F,8F)-5 (4-14) 4% 3-HDhB(2F,3F)—O2 (4-16) 5% 3-HchB(2F,3F)—O2 (4-19) 5%

NI=71.5° C.; Tc<−20° C.; η=17.9 mPa·s; Δn=0.087; Δε=−4.4; Vth=1.90 V; γ1=105.0 mPa·s.

The dielectric anisotropy (Δε) of the composition in Comparative Example 1 was −3.9. On the other hand, the dielectric anisotropy of the composition in Example 1 was −4.5. Thus, the composition in Example had a larger negative dielectric anisotropy in comparison with the composition in Comparative Example. Accordingly, the liquid crystal composition of the invention is concluded to have superb characteristics.

Although the invention has been described and illustrated with a certain degree of particularity, it is understood that the disclosure has been made only by way of example, and that numerous changes in the conditions and order of steps can be resorted to by those skilled in the art without departing from the spirit and scope of the invention.

INDUSTRIAL APPLICABILITY

A liquid crystal composition of the invention satisfies at least one of characteristics such as a high maximum temperature, a low minimum temperature, a small viscosity, a suitable optical anisotropy, a large negative dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light, a high stability to heat, or the like, or has a suitable balance regarding at least two of the characteristics. A liquid crystal display device including the composition has characteristics such as a short response time, a large voltage holding ratio, a low threshold voltage, a large contrast ratio and a long service life, and thus can be used for a liquid crystal projector, a liquid crystal television and so forth. 

What is claimed is:
 1. A liquid crystal composition that has a negative dielectric anisotropy and contains at least one compound selected from compounds represented by formula (1) and having a negative dielectric anisotropy as a first component and at least one compound selected from compounds represented by formula (2) as a second component:

wherein, in formula (1) and formula (2), R¹ and R² are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkenyloxy having 2 to 12 carbons, or alkyl having 1 to 12 carbons in which at least one hydrogen is replaced by fluorine or chlorine; R³ and R⁴ are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkyl having 1 to 12 carbons in which at least one hydrogen is replaced by fluorine or chlorine or alkenyl having 2 to 12 carbons in which at least one hydrogen is replaced by fluorine and chlorine; ring A and ring C are independently 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 3,4-dihydro-2H-pyrane-2,5-diyl, 1,4-phenylene, 1,4-phenylene in which at least one hydrogen is replaced by fluorine or chlorine, naphthalene-2,6-diyl, naphthalene-2,6-diyl in which at least one hydrogen is replaced by fluorine or chlorine, chroman-2,6-diyl, or chroman-2,6-diyl in which at least one hydrogen is replaced by fluorine or chlorine, in which at least one of ring A and ring C is 3,4-dihydro-2H-pyrane-2,5-diyl; ring B is 2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5-trifluoronaphthalene-2,6-diyl, or 7,8-difluorochroman-2,6-diyl; Z¹ and Z² are independently a single bond, ethylene, carbonyloxy or methyleneoxy; a is 1, 2 or 3; b is 0 or 1; and a sum of a and b is 3 or less.
 2. The liquid crystal composition according to claim 1, containing at least one compound selected from the group of compounds represented by formula (1-1) to formula (1-7) as the first component:

wherein, in formula (1-1) to formula (1-7), R¹ and R² are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkenyloxy having 2 to 12 carbons, or alkyl having 1 to 12 carbons in which at least one hydrogen is replaced by fluorine or chlorine.
 3. The liquid crystal composition according to claim 1, wherein an amount of the first component is in the range of 5% by weight to 40% by weight and an amount of the second component is in the range of 10% by weight to 60% and by weight, based on the weight of the liquid crystal composition.
 4. The liquid crystal composition according to claim 1, containing at least one compound selected from compounds represented by formula (3) as a third component:

wherein, in formula (3), R⁵ and R⁶ are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkyl having 1 to 12 carbons in which at least one hydrogen is replaced by fluorine or chlorine or alkenyl having 2 to 12 carbons in which at least one hydrogen is replaced by fluorine or chlorine; ring C and ring D are independently 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene or 2,5-difluoro-1,4-phenylene; Z³ is a single bond, ethylene or carbonyloxy; d is 1, 2 or 3; wherein ring D is 1,4-phenylene when d is
 1. 5. The liquid crystal composition according to claim 4, containing at least one compound selected from the group of compounds represented by formula (3-1) to (3-12) as the third component:

wherein, in formulas (3-1) to (3-12), R⁵ and R⁶ are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkyl having 1 to 12 carbons in which at least one hydrogen is replaced by fluorine or chlorine or alkenyl having 2 to 12 carbons in which at least one hydrogen is replaced by fluorine or chlorine.
 6. The liquid crystal composition according to claim 4, wherein an amount of the third component is in the range of 5% by weight to 40% by weight based on the weight of the liquid crystal composition.
 7. The liquid crystal composition according to claim 1, containing at least one compound selected from compounds represented by formula (4) as a fourth component:

wherein, in formula (4), R⁷ and R⁸ are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkenyloxy having 2 to 12 carbons, or alkyl having 1 to 12 carbons in which at least one hydrogen is replaced by fluorine or chlorine; ring E and ring G are independently 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,4-phenylene, 1,4-phenylene in which at least one hydrogen is replaced by fluorine or chlorine, naphthalene-2,6-diyl, naphthalene-2,6-diyl in which at least one hydrogen is replaced by fluorine or chlorine, chroman-2,6-diyl, or chroman-2,6-diyl in which at least one hydrogen is replaced by fluorine or chlorine; ring F is 2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5-trifluoronaphthalene-2,6-diyl or 7,8-difluorochroman-2,6-diyl; Z⁴ and Z⁵ are independently a single bond, ethylene, carbonyloxy or methyleneoxy; p is 1, 2 or 3; q is 0 or 1; and a sum of p and q is 3 or less.
 8. The liquid crystal composition according to claim 7, containing at least one compound selected from the group of compounds represented by formula (4-1) to formula (4-19) as the fourth component:

wherein, in formula (4-1) to formula (4-19), R⁷ and R⁸ are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkenyloxy having 2 to 12 carbons, or alkyl having 1 to 12 carbons in which at least one hydrogen is replaced by fluorine or chlorine.
 9. The liquid crystal composition according to claim 7, wherein an amount of the fourth component is in the range of 10% by weight to 70% by weight based on the weight of the liquid crystal composition.
 10. The liquid crystal composition according to claim 4, containing at least one compound selected from compounds represented by formula (4) as a fourth component:

wherein, in formula (4), R⁷ and R⁸ are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkenyloxy having 2 to 12 carbons, or alkyl having 1 to 12 carbons in which at least one hydrogen is replaced by fluorine or chlorine; ring E and ring G are independently 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,4-phenylene, 1,4-phenylene in which at least one hydrogen is replaced by fluorine or chlorine, naphthalene-2,6-diyl, naphthalene-2,6-diyl in which at least one hydrogen is replaced by fluorine or chlorine, chroman-2,6-diyl, or chroman-2,6-diyl in which at least one hydrogen is replaced by fluorine or chlorine; ring F is 2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5-trifluoronaphthalene-2,6-diyl or 7,8-difluorochroman-2,6-diyl; Z⁴ and Z⁵ are independently a single bond, ethylene, carbonyloxy or methyleneoxy; p is 1, 2 or 3; q is 0 or 1; and a sum of p and q is 3 or less.
 11. The liquid crystal composition according to claim 1, containing at least one polymerizable compound selected from compounds represented by formula (5) as an additive component:

wherein, in formula (5), ring K and ring M are independently cyclohexyl, cyclohexenyl, phenyl, 1-naphthyl, 2-naphthyl, tetrahydropyran-2-yl, 1,3-dioxane-2-yl, pyrimidine-2-yl or pyridine-2-yl, and in the rings, at least one hydrogen may be replaced by fluorine, chlorine, alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkyl having 1 to 12 carbons in which at least one hydrogen is replaced by fluorine or chlorine; ring L is 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, naphthalene-1,2-diyl, naphthalene-1,3-diyl, naphthalene-1,4-diyl, naphthalene-1,5-diyl, naphthalene-1,6-diyl, naphthalene-1,7-diyl, naphthalene-1,8-diyl, naphthalene-2,3-diyl, naphthalene-2,6-diyl, naphthalene-2,7-diyl, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl or pyridine-2,5-diyl, and in the rings, at least one hydrogen may be replaced by fluorine, chlorine, alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkyl having 1 to 12 carbons in which at least one hydrogen is replaced by fluorine or chlorine; Z⁶ and Z⁷ are independently a single bond or alkylene having 1 to 10 carbons, and in the alkylene, at least one —CH₂— may be replaced by —O—, —CO—, —COO—, or —OCO—, at least one —CH₂—CH₂— may be replaced by —CH═CH—, —C(CH₃)═CH—, —CH═C(CH₃)— or —C(CH₃)═C(CH₃)—, and in the groups, at least one hydrogen may be replaced by fluorine or chlorine; P¹, P² and P³ are independently a polymerizable group; Sp¹, Sp² and Sp³ are independently a single bond or alkylene having 1 to 10 carbons, and in the alkylene, at least one —CH₂— may be replaced by —O—, —COO—, —OCO— or —OCOO—, at least one —CH₂—CH₂— may be replaced by —CH═CH— or —C≡C—, and in the groups, at least one hydrogen may be replaced by fluorine or chlorine; g is 0, 1 or 2; and h, j and k are independently 0, 1, 2, 3 or 4, and a sum of h, j and k is 1 or more.
 12. The liquid crystal composition according to claim 11, wherein, in formula (5), P¹, P² and P³ are independently a polymerizable group selected from the group of groups represented by formula (P-1) to formula (P-6):

wherein, in formula (P-1) to formula (P-6), M¹, M² and M³ are independently hydrogen, fluorine, alkyl having 1 to 5 carbons, or alkyl having 1 to 5 carbons in which at least one hydrogen is replaced by fluorine or chlorine; and in formula (5), when all of h pieces of P′ and k pieces of P³ are a group represented by formula (P-4), at least one of h pieces of Sp′ and k pieces of Sp³ is alkylene having 1 to 10 carbons in which at least one —CH₂— is replaced by —O—, —OCO—, —OCO— or —OCOO—.
 13. The liquid crystal composition according to claim 11, containing at least one polymerizable compound selected from the group of compounds represented by formula (5-1) to formula (5-27) as the additive component:

wherein, in formula (5-1) to formula (5-27), P⁴, P⁵ and P⁶ are independently a polymerizable group selected from the group of groups represented by formula (P-1) to formula (P-3);

wherein, in formula (P-1) to formula (P-3), M¹, M² and M³ are independently hydrogen, fluorine, alkyl having 1 to 5 carbons, or alkyl having 1 to 5 carbons in which at least one hydrogen is replaced by fluorine or chlorine; and in formula (5-1) to formula (5-27), Sp¹, Sp² and Sp³ are independently a single bond or alkylene having 1 to 10 carbons, and in the alkylene, at least one —CH₂— may be replaced by —O—, —COO—, —OCO— or —OCOO—, at least one —CH₂—CH₂— may be replaced by —CH═CH— or and in the groups, at least one hydrogen may be replaced by fluorine or chlorine.
 14. The liquid crystal composition according to claim 11, wherein an amount of addition of the additive component is in the range of 0.03% by weight to 10% by weight based on the weight of the liquid crystal composition.
 15. A liquid crystal display device, including the liquid crystal composition according to claim
 1. 16. The liquid crystal display device according to claim 15, wherein an operating mode in the liquid crystal display device includes an IPS mode, a VA mode, an FFS mode or an FPA mode, and a driving mode in the liquid crystal display device includes an active matrix mode.
 17. A liquid crystal display device having a polymer sustained alignment mode, wherein the liquid crystal display device includes the liquid crystal composition according to claim
 1. 18. A liquid crystal display device having a polymer sustained alignment mode, wherein the liquid crystal display device includes the liquid crystal composition according to claim 11, and the polymerizable compound in the liquid crystal composition is polymerized.
 19. The liquid crystal composition according to claim 1, containing at least one compound selected from the group of compounds represented by formula (1-4) to formula (1-6) as the first component:

wherein, in formula (1-4) to formula (1-6), R¹ and R² are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkenyloxy having 2 to 12 carbons, or alkyl having 1 to 12 carbons in which at least one hydrogen is replaced by fluorine or chlorine. 